Box folding machine



pt. 3, 19 R. J. .GRUENBERG ETAL 2,213,494

BOX FOLDING MACHINE 7 Filed June 15, 1958 8 Sheets-Sheet 1 FIG.

ol O-I I I INVENTORSZ AOLiJL. J. GRUENBERG BY WILLIAM E. FORMWAY ATTORNEY.

p 3. 1940" R. J. GRUENBERG ET AL I 2,213,494

BOX FOLDING MACHINE Filed June 15, 1938 I 8 Sheets-Sheet 2 RAOUL J. GRUENBERG WILLIAM E. FORMWAY ATTORNEY INVENTORS:

Sept. 3. 1940.

RJJ. GRUENBERG ET AL B OX FOLDING MACHINE Filed June 15, 1938 a sna s-sheet s pt. 3, 1940- R. .1. GRUENBERG ET AL 2,213,494

BOX FDLDING MACHINE 7 Filed June 15, 19s: s Sheet s-Sheet 5 F l G. 6.

K INVENTORS RAOUL J. GRUENBE'RG BY WILLIAM E. FQRMWAY ATTORNEY.

Sept- 3. -9 R, J. GRUENBERG ET AL BOX FOLDING MACHINE I Filed June 15, less v a Sheets-Sheet 6 s e .TRY N.

a EA M N W/ mm G .I .r M m L mm Rw ATTORN EY pt- 3. 1940. R. J. GRUENBERG ET AL BOX FOLDlgNG MACHINE Fileq June 15, 1933 Sept. '3, 1940 R. J. GRUENVBERGV ET AL 2,213,494

BOX FOLDIHQ MACHINE Filed June 15, 1938 s Sheets-Sheet a- INVENTOR S: RAOUL J. GRUENBEIRG WILLIAM E. FORMWAY ATTORNEY tical section on the line Patented Sept. 3, 1940 PATENT ,OFFlC-E;

2,213,494 BOX FOLDING MACHINE Raoul J.

Gruenberg, San Francisco, and William E. Formway, Los Altos, Calif., assignors to Cumlokt Company, San Francisco, Calib, a corporation ApplicationJune 15, 1938, Serial No. 213,804

15 Claims.-

This invention relates to improvements in box folding machines and, more particularly, to a machine for folding boxes of the class shown in the patents to Edgar L. Stern, Number 1,463,448, dated July box, and Stern and Gruenberg, No. 2,008,935, dated July 23, 1935, entitled Folding box, and the machine for folding this type of box disclosed in the patent to John William Low, Number 1,937,027, dated Nov. 28, 1933, entitled Box folding machine. I

Among the objects of the invention is to provide a machine that will automatically feed and fold box blanks seriatim and interlock the tabs and slots to form fully assembled collapsed boxes ready for immediate use when opened.

Another object is to reduce the cost of production and increase the demand for folded boxes.

Another object is to fold and interlock the boxes as a continuous function of the machine.

Other objects and advantages will appear as the description progresses.

In this specification and the accompanying drawings, the invention is disclosed in its preferred form. But it is to be understood that it is not limited to this form, because it maybe modified within the purview of the claims following the description.

In the eight sheets of drawings:

Fig. 1 is a plan view from above of the receiving end of a box folding machine constructed in accordance with this invention.

Fig. 2 is to read as a continuation of Fig. 1 and shows the tab interlocking and delivery end of the machine.

Fig. 3 is a side elevation of the receiving end of the machine as shown in Fig. 1.

Fig. 4 is a side elevation of the tab interlocking and delivery end of the machine, as shown in Fig. 2.

Fig. 5 is an enlarged detail longitudinal vertical section of the folded box flattening mechanism at the delivery end of the machine.

Fig. 6 is'a-n enlarged detail in transverse ver- VI-VI in Fig. l of the blank curling mechanism.

Fig. '7 is a similar view taken on the line VII-VII in Fig. 2 of the slot opening, tongue inserting and end folding mechanism. 7

Fig. 8 is an. enlarged detail in longitudinal vertical section showing the cam actuated and folding mechanism, approaching the folding of the rear end of a box.

Fig. 9 is a similar view of the opposed end folder showing it in the operative position fol- 31, 1923, entitled Foldinglowing the folding and interlocking of the front end. of the box.

Fig. 10 is a fragmentary detail showing the slot opener in operative position, diagrammatically' indicating the entry of the locking 5 tongue into the slot.

Fig. 11 is a kinematic diagram plotting the curvilinear action of the slot opener.

Fig. 12 is a fragmentary plan view of one die cut corner of the box blank.

Fig. 13 is a similar view of the same in the folded, interlocked and collapsed condition.

Fig. 14 is a detail in plan view of a modified mechanism for opening the slots in the box blank preparatory to the entry of the locking tongues. 15

In detail, the construction illustrated in the drawings, referring first to Fig. 12, comprises a box blank of conventionalboxboard a. This is longitudinally scored as at b to form side panels 0 on opposite sides of its length. The opposite 2 ends of all these side panels 0 have oppositely disposed oblique slots such as d, shaped as shown for reasons set forth in detail in the above patents. The end margins of the blank are transversely scored as at e, to form the opposite end panels I. These panels are traversed by the longitudinal score lines D to form bendable hinge lines 9 for the tongues h to engage the slots d at the four corners of the box respectively, the four corners being similar in structure and operation.

Departing from the usual practice the present boxes are shaped by folding the side panels 0 inwardly and downwardly. During the infolding of the sides, the slots are forced open to receive the tongues it brought into position above the side panels 0 when the end panels 1 are folded inwardly. Completion of the infolding of the ends I forces the tongues h backwardly and completely through their respective slots 11. and to a position beneath the end panels where they lie contiguous to the plane of the blank 11.

Fig. 10 shows the tongue it about to enter the slot d. The interlocking of the tongues and slots at the four corners of the boxin themanner described holds the sides 0 and the ends 1 col lapsed against the plane a. of the blank which then forms the bottom of the box, as shown in Fig. 13.

In the present machine one end of the box at a time is infolded and interlocked by the machine. This enables one slot opening and interlocking mechanism on each side of the machine to act simultaneously on the respective ends of the box blanks as they pass continuously through the machine.

'21 on the main frame.

Referring next to Figs. 1, 2, 3, and 4, the structure of the machine comprises a rigid main frame having the parallel channel bars .I and 2 properly trussed and cross braced to-form the bed of the machine, with the transverse overhead trusses 3, 4, 5, 6, 1 fixed thereto. This bed is supported on the pairs of supporting legs, such as 8, 9, III, ll, [2, I3 properly fixed and braced to the bars I, 2 and anchored to sills or the floor :0.

At the front end, see Fig. 3, the side extension bars l'l, l5 are added to the length of the side bars I, 2 respectively, to which the bearing brackets such as I6 are bolted to support the idle shaft l1 upon which the laterally spaced sprockets l8, I8 are fixed parallel with their respective side bars I, 2.

The driven shaft 20 at the delivery end of the machine is similarly mounted in the brackets 2|, 22 fixed to the supporting legs l2 and I3 respectively, Fig. 2. This shaft is driven by the motor 23, through the \l-belt 24 and the pulley 25 on the counter-shaft 26 mounted in bearings This counter-shaft has the pinion 28 enmeshed with the spur gear 30 fixed on the shaft 20. The pair of sprockets 29, 30 are fixed on the shaft 20 in alinement with the sprockets I 8, l8 on the front shaft H.

The conveyor feed for the blanks a consists of the pair of endless sprocket chains 3|, 32, preferably of the roller type, encircling their respective sprockets I8, 29 and I8, 30. The top reachesof these chains run on their respective tracks 33, 33' supported on the brackets 34, 34' extending inwardly from the side bars I, 2. The rollers of the sprocket links reduce the friction between the chains and the tracks. The lower reaches of the conveyor hang suspended below its said sprockets to maintain the required tension on the chains 3 I, 32.

At proper intervals, determined by the length of the box blanks a, the end bending units A, B

.are mounted on the chains 3|, 32 across the top of the conveyor, see Figs, 1, 2. These end benders are alike in construction and operation, except that alternate units act upon the opposite ends of the box blanks and are actuated by similar cam sets located on opposite sides of the main frame. It is deemed sufficient to describe one end bender in detail, similar parts in the others being identified by the same reference numerals with the omission of the prime signs These benders' are duplicated at intervals on the conveyor.

Figs. 6, 7 are different operative views of the bender B that has the square offset shaft '36 with its reduced opposite ends 31 and 38 oscillatable in their bearings 39', 40' fixed on the brackets 4|; 42' fixed to links of their respective chains 3|, 32 of the conveyor.

The end bender A has the crank head 43 fixed on the end 31 of the offset shaft 36. This head has the studs 44, 45, 46 extending therefrom and having the antifriction rollers thereon. The shaft 36 has the bending vane 41 fixed thereon, see also Fig. 9.

' I In advance of and parallel with the end benders are the pressure bars such as 48', best illustrated in connection with the end bender B, mounted upon the brackets 49', 50 fixed to links of their respective chains, as 32. In Fig. 9 the bender A is approaching its operating cam 5| fixed on the face of the plate 56 mounted on the main frame lateral to the conveyor. The roller 44 engages the cam 5| thus swinging the vane 41 backward while the stud 45 passes under this cam 5|, until it engages the inclined cam 52 up which it rides to further lift the vane 41 while the studs 44, 46 pass under the incline 52 to hold the vane in operative position, as shown in dot-dash lines.

At the end of the functional travel of the bender A, the stud 46 engages the decline cam 53 to reverse the swing of the vane 41. When the stud 46 strikes the incline 54, it throws the stud 45 downward beneath the decline cam 55, which completely restores the end bender unit to inoperative position with the vane 41 retracted as in full lines Fig. 9.

The end bender unit B, Fig. 8, is similar in construction to the bender A above described,

except that it operates contrawise to the travel of the box blank. The bending vane 41' is fixedto the offset shaft 36', oscillated by the crank head 43' fixed on the end 38' of this shaft. The head has the studs 44', 45'. The stud 44. is depressed by the cam 5| fixed on the plate 56'. When the first stud 44 strikes under the inclined cam 5|,

the offset shaft 36 is rotated 90 degrees. The stud 44' then strikes theincline 52' which carries the vane 41 through an additional 90 degrees, bringing the roller 45' into. engagement with the substantially horizontal continuation 52" of the incline 52'. At the end of the horizontal travel, the stud 45' passes off the plane52" and rides up the inclined cam 53' until it engages the declined cam which restores the offset shaft 36' and vane 41 to the inoperative position shown in Fig. 8. The spring guard 54' engages the roller 45' to safeguard against its overcarrying above the plane of the declined cam 55.

Intermediate the various end bending units AB, the conveyor is provided with the cross cleats such as 60, coplanar with the pressure bars 48, to receive the plane a of the box blanks, see Fig. 3. The opposite ends of these cleats are bent downward and fixed to individual links of their respective chains 3|, 32 to form successive flexible gridliketables between the end benders.

AB, duplicated throughout the length of the conveyor.

To the rear of each bender A is an upstanding gage 6| to center the box blank between the end benders and to cause the "blanks to advance with the conveyor against the resistance of the sidefolding shrouds 62, 63. The front ends of these shrouds overhang and are substantially parallel with the plane of the conveyor, beginning at the overhead truss 3, Fig. 1. Their outer edges 64, respectively are helically curled upwardly about ninety degrees at the second truss 4, then inwardly to substantially one hundred eighty degrees, just beyond the truss 6 to the cross bracket 6', the opposed shrouds having substantially one half turn in their lengths tofold the side inward and downward against the plane of the blank a.

The vertical side plates 66, 61 extend between the trusses 6, 1 above the plane of the cleats 60 of the conveyor. When the side panels c, c emerge from the curling shrouds, the advance tongues 71., h snap upwardly to vertical positions against the plates 66, 61 respectively, as the blank advances toward the slot opening units C, D, see Fig. 2.

The slot openers C, D, located on opposite sides of the conveyor, are alike in structure and operation, except that they operate in opposed relation to each other and the box blank. The slot opener C will be described in detail. Similar parts in D will be given the common reference numerals panels 0, c

. bracket ing mechanisms at C-D,

the counter-shaft 20 and a sprocket on the shaft 68. The bevel gear 10 is fixed on the jack shaft 68 and meshed with the similar gear 'II on the vertical shaft I2, mounted in the bearing bracket 13 on the main frame. The sprocket I4 is fixed on the upper end of this vertical shaft 12, see Fig. 2. The lateral extension 15 of the vertical I3 provides suitable mounting for the smaller driven sprocket I6 driven by the sprocket I I and chain 1'I. The speed ratio of these sprockets is two to one.

The crank pin I8 is eccentrically fixed in the sprocket I4 and the rotatably mounted in the sprocket I6 eccentric to its center. Thesesprockets function in effect as cranks. The reciprocating arm is pivoted on the crank pin I8 and has a tail extension 8| slidable through and deflected by the planetary pivot I9 on the sprocket I8. This arrangement of parts gives a novel mechanical curvilinear movement to'the head 82 on the arm 80. Fig. 11 is a kinematic plot of this movement, showing the reciprocations and the advance and retractive movements of the head 82 with respect to the travel of the conveyor. The head 80 has a flat sliding guide pivot I9 is.

ipcar shaped slot plate 83 with tapering upturned edges 84, 85 on opposite sides of the fin 86 inclined from the plane of the slot plate 83. These plates 83, 83 advance across the traveling folded edges 12, b on top of the side panels c, c and through the slots d, d respectively, see Fig. 10, being driven in unison with the advance of the conveyor by the common prime-mover 23.

To insure the entry of the slot opening plates 83, 83' into the slots d, d, the side panels 0, c, emerging from the shrouds, ride up over the cross bars 81, 88 on the arm 89, pivoted under the truss 6, see Figs. 2 and 7. These cross bars are adapted to uphold the edges of and present the side panels 0, c at an angle to the approach of the slot opening plates 83, 83" to assure'the proper entry edges 84, 85 into the slots. This condition maintains until the end folder B comes into position, at which time the approaching gage 8| kicks up the arm 89 to lift the bars 81, 88 clear of the side panels c, c the plates 83, 83'.

After passing the slot opening and interlockthe box, transformed from the blank (1., passes beneath the overhead depressing bars 90, 9I extending longitudinally through the truss I, and supported on the crossbar I located near the end of the bars 90, 9|. The roller 92 is fixed on the shaft 93, see Figs. 2, 3. This pressure roller 92 registers vertically wi h a similar lower roller 94 on-the shaft H3, Figs. 4, 5, between which the folded edges b, b and e, e are compressed to maintain the boxes in interlocked and collapsed condition. The shafts that are still held depressed by of the plates and the wedge shape seeFigs. 7 and 10.

88, 99 overhanging the edges of the conveyor at the level of the cleats 89. These plates have upstanding vertical planes I00, IOI, see Fig. 1, to aline the edges of the blanks a, with the edge curling shrouds 62, 63. The machine may be automatically fed by a conventional pneumatic press feeder arranged'at the end of the machine, or by hand.

The machine operates substantially as follows: If hand fed, the operator preferably stands atO and reaches across the machine to the stacked blanks on the opposite side at P, see Fig. l. A single blank from the top of the stack is laid lengthwise on the plates 98, 99 between the vertical planes I00, IOI, where it lies until'the conveyor rising on the sprocket I9, brings a gage BI up behind the blank, sliding it forward on to the forward ends of the side curling shrouds 62, 83. The advancing side panels 0, c ride up the helical planes of the shrouds which bend the blank on the longitudinal score lines b, b, see Fig. 6'. The pressure bars I03, I04, having the upturned ends I05, I06 respectively, are mounted beneath the trusses 3, 4, 5 on brackets such as I01. The upturned ends I05, I06 are joined by the guard plate I08 which guides the box blanks beneath the pressure bars. These bars I03, I04 bear against the upper plane of the blank a adjacent the score lines I), I) while the side panels 0, c are being curled upward and inward by the shrouds 62, 63. The center portion of the blank a is prevented from buckling upward by the down pressure of the spring I09, fixed beneath the guard I08, during the passage of the box blank.

Should a blank buckle and jam in passing beneath the shrouds, it will rise and bear under the contact finger H0. This finger is separated by the dielectric block III fixed under the truss 3 from a similar contact H2. These contacts are adapted to ground a suitable relay circuit controlling the motor 23 and stop the machine, permitting theremoval of the damaged blank.

Emerging from the shrouds 82, 63 at 6', the forward tongues h, h snap up vertically against the vertical plates 68, 61, permitting the lifter bars 81, 88 to pass beneaththe ends of the side panels 0, c. In synchronism with the entrance of the lifter bars, the points of the plates 83, 83'

enter and spread the first pair of slots d, d before the end bender A has entered its sequence which throws the vertical tongues h, h forward and downward against the fins 89, 86' respectively, which deflects the tongues into the slotsd, d, The continued swing of the vane .41 fiattens the end i down on top of the side panels 0, c, completing the interlocking of the tongues curled into the slots, just as the slot openers 83, 83 withdraw from the slots, and the end of the box passes beneath the pressure bars 90, 9| to maintain the interlocked condition.

In the meantime, the gage 6| kicks up the arm 89, freeing the bars-8'I, 88 as the rear end bender B approaches the slot openers C, D, which thrust the plates 83, 83. into the second pair of slots 11, d, see Fig. '7. This opens the slots, permitting the pair of tongues h, h, brought into position by the vane 41, to enter the slots (1, (1 respectively, as the end bender B enters its sequence of cams 5I'-55'.

coincidentally with the interlocking of the I tongues and slots on the rear end of the box, the

described. The folded, interlocked, and collapsed boxes emerging from the machine are stacked in a'manner to prevent them snapping open, as fully described in the patents referred to in the preamble. Such boxes snap open ready for use when the sides 0, c are lifted.

The slot opening and closing mechanism C, D, shown and described, operate on the pairs of slots d at the opposite ends of the blank seriatim as the blank passes through the machine. A modification is shown in Fig. 14 in which the cross head 82.1: on the arm :2: has a pair of plates 83x, 83am fixed thereon. These plates are thus adapted to simultaneously enter the slots d, d at both ends of the blank to condition them to receive the tongues h simultaneously. The sprockets 14x, 16:: are of the same diameter for obvious reasons. With appropriate timing of the end benders A, B, both ends of the box can be interlocked simultaneously to speed up production.

By arranging gumming means on the arms 82, 82', instead of the slot opening heads 83, 83', this machine is equally adapted to the folding and adhering of end tabs on the end panels to the ends of the side panels on similar boxes where the interlocked tongues and slots are less desirable. i

As used throughout the specification and claims continuously means without interruption.

Having thus described this invention, what we claim and desire to secure by Letters Patent is:

1. A box folding machine including a conveyor adapted to continuously move a box blank; means for folding and interlocking the sides and ends of the box in a plane substantially parallel with the box bottom during the continuous travel of the box on said conveyor.

2. A box folding machine including a conveyor adapted to carry a box blank having side and end panels with tongues and slots respectively; means for simultaneously folding the slotted sides inwardly toward the bottom of the box; lateral means adapted to enter and withdraw from said slots during the passage of said blank; and end folding means adapted to curl said tongues though said slots and lay said ends over the ends of said sides.

3. A box folding machine including a stationary frame; a conveyor on said frame adapted to carry a box blank having side and end panels with tongues and slots respectively; side panel folding means and slot opening means on said frame; and end folding means on said conveyor adapted to interlock said tongues and slots in synchronism with the operation of said slot opening means.

4. A box folding machine including a stationary frame; a conveyor on said frame adapted to carry a box blank having side and end panels with tongues and slots respectively; side panel folding means on said frame; lateral means on said frame adapted to enter and withdraw from said slots during the passage of said blank; and end folding means adapted to curl said tongues through said slots in synchronism with said lateral means.

5. A box folding machine including a stationary frame; a conveyor on said frame adapted to carry a box blank having side and end panels with tongues and slots respectively; slot opening means on opposite sides of said conveyor each comprising a crank pin and a pivot driven 1|, in unison with said conveyor; an arm pivoted on said crank pin and slidable in said pivot and having a head adapted to enter and withdraw from the slots in the opposite side panels respectively; and end folding means synchronized with said slot' opening means and adapted to interlock said tongues and slots.

6. A box folding machine including a frame; a

conveyor'on said frame adapted to carry a box.

blank having side and end panels with tongues and slots respectively; slot openers on said frame movable into and out of said slots during the passage of said blank; and end folding means adapted to interlock said tongues and slots.

7. A box folding machine including a frame; a conveyor on said frame; brackets on opposite sides of said frame, each bracket having a pair of cranks driven in unison with said conveyor and having a crank pin and a pivot thereon-respectively; an arm pivoted on said pin and slidable in the said pivot and having a slot opening head on one end; and end folding means operated in synchronism with said arms.

8. A box folding machine including a frame; a conveyor adapted to carry a box blank; side and end folding means in operative relation to said blank respectively; a pair of cranks on said frame alined transversely to the travel of said conveyor and driven in unison therewith and at different speeds relative to each other; an arm pivoted on one of said cranks and, slidable in a pivot on the other crank; and a slot opening head on said arm in operative relation to said blank. V

9. A box folding machine including a frame; a

"conveyor on said frame and adapted to carry a box blank having side and end panels with tongues and slots respectively; slot openers on said frame movable into and out of said slots during the passage of said blank; end folding means transversely pivoted on said conveyor and engaging actuating means on said frame and adapted to interlock said tongues and slots in.

synchronism with the operation of said slot openers.

10. A box folding machine including a frame and a conveyor adapted to carry a box blank having side and end panels with tongues and slots respectively; side panel folding shrouds on the opposite sides of said frame in operative relation to said blank; means for holding the side edges above the bottom of said box; slot opening means on the opposite side of said frame and having tongue guiding fins thereon; end folding means transversely pivoted on said conveyor at the opposite ends of said blank respectively and adapted to curl said tongues against said fins and into said slots; trips on said frame in operative relation to said end folding means; and means for compressing the folded box.

11. A machine for opening the slots in folding boxes including a frame; a conveyor on said frame adapted to carrya box blank having slots therein; a pair of cranks on said frame alined transversely to the travel of said conveyor and driven in unison therewith at different speeds relative to each other; an arm pivoted on one of said cranks and slidable in a'pivot on the other crank; and a slot opening head on one end of said arm.

taneously curling the tongues through said slots in a backwardly direction.

13. The method of interlocking a folding box having side and end panels with tongues and slots respectively, consisting in simultaneously folding the slotted sides inwardly substantially parallel with the plane of the bottom of the box; then folding the end panels inwardly over the side panels and interlocking the tongues in said slots while the box blank moves continuously forward.

14. The method of interlocking a folding box having side and endpanels with tongues and slots respectively consisting in folding said panels inwardly, then passing said tongues inwardly and backwardly through said slots while the box blank is in collapsed condition and in continuous motion through a box folding machine.

15. The method of interlocking a folding box having side and end panels with tongues and slots respectively consisting in folding said panels inwardly, then passing said tongues through said slots toward said end panels while the box blank is in collapsed condition and in continuous 10 motion through a box folding machine.

RAOUL J. GRUENBERG. WILLIAM E. FORMWAY. 

